This is the book doctors use to define mental illness--and it's all about to change

The mind, in our modern conception, is an array of circuits we can manipulate with chemicals to ease, if not cure, depression, anxiety and other disorders. Drugs like Prozac have transformed how we respond to mental illness. But while this revolution has reshaped treatments, it hasn't done much to help us diagnose what's wrong to begin with. Instead of ordering lab tests, psychiatrists usually have to size up people using subjective descriptions of the healthy vs. the afflicted.

Which is why the revision of a single book is roiling the world of mental health, pitting psychiatrists against one another in bitter...